strtok.c in VS

/* Copyright (c) Microsoft Corporation. All rights reserved. */
 
#include <string.h>
 
/* ISO/IEC 9899 7.11.5.8 strtok. DEPRECATED.
 * Split string into tokens, and return one at a time while retaining state
 * internally.
 *
 * WARNING: Only one set of state is held and this means that the
 * WARNING: function is not thread-safe nor safe for multiple uses within
 * WARNING: one thread.
 *
 * NOTE: No library may call this function.
 */
 
char * __cdecl strtok(char *s1, const char *delimit)
{
    static char *lastToken = NULL; /* UNSAFE SHARED STATE! */
    char *tmp;
 
    /* Skip leading delimiters if new string. */
    if ( s1 == NULL ) {
        s1 = lastToken;
        if (s1 == NULL)         /* End of story? */
            return NULL;
    } else {
        s1 += strspn(s1, delimit);
    }
 
    /* Find end of segment */
    tmp = strpbrk(s1, delimit);
    if (tmp) {
        /* Found another delimiter, split string and save state. */
        *tmp = '\0';
        lastToken = tmp + 1;
    } else {
        /* Last segment, remember that. */
        lastToken = NULL;
    }
 
    return s1;
}